272 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 16 
is used. To avoid variation in strength of solution all tests each year 
are made from the same tank of spray solution kept agitated through¬ 
out the test. The later summer applications like the first are given to 
the entire orchard alike. 
Usually three pressures, 75 pounds, 150 pounds, and 250 pounds 
have been used. The small Vermorell, disc, and Bordeaux nozzles and 
the spray gun have all been tested out. 
In a few days after the calyx spray is applied a counted number of 
apples are collected from each of the experimental trees. Two hundred 
and fifty and five hundred apples are used for the tests to determine the 
quantity of arsenic in the calyx cup. For the calyx cup tests, the tip 
of each apple is pealed, and the sepals, exposed part of pistal and stamen 
bars removed and the calyx cup with a small part of the flesh at the tip 
of the young apple is then removed for later chemical tests. These are 
dried and later tested for total arsenical content of sample. 
In the fall the crop from each tree is gathered and each apple carefully 
examined for every type of injury by insect or fungus disease, a separate 
record being kept of all calyx end worms. 
Experimental Results 
It is not the intention of the writer to insert here detailed tables with 
results of all the years tests but merely to include figures on the 1920 
experiment which is one of the completest. 
Table No. I. 
Pressure 
Nozzle 
No. 
calyx 
cups 
Weight of 
Sample 
Percent 
arsenous 
Oxide 
Total 
AS 2 O 3 
Quantity 
per 
Calyx 
% 
Apples 
with 
calyx 
worms 
250 lbs. 
Run 
450 
4.7249 
1.128 
.05329 
.0001184 
3.63 
t i t t 
bordeaux 
400 
5.4703 
1.353 
.07401 
.0001850 
5.62 
a a 
disk 
410 
5.1671 
1.006 
.05198 
.0001267 
6.00 
150 “ 
gun 
450 
5.4500 
1.627 
.08867 
.0001970 
1.92 
it a 
bordeaux 
450 
5.6576 
1.013 
.04718 
.0001048 
3.01 
it tt 
disk 
450 
4.8520 
1.249 
.06060 
.0001346 
2.59 
100 “ 
gun 
250 
2.8373 . 
0.510 
.01447 
.0000578 
9.25 
It tt 
bordeaux 
250 
2.3250 
1.433 
.03331 
.0001332 
4.55 
it it 
disk 
250 
2.6520 
2.660 
.07054 
.0002805 
4.20 
In this experiment the greatest quantity of arsenic per calyx cup wa 
deposited with the lower pressure, 100 pounds and the disc nozzles 
The spray gun with 150 pounds pressure and Bordeaux nozzle with 250. 
pounds pressure gave almost equal quantities but much less than the disc 
and 100 pounds pressure. The poorest results were secured with the 
spray gun at 100 pounds pressure. Except for the four above mentioned 
cases, the quantity of arsenic is practically the same in all the tests. A 
